Two-dimension Cd-N co-doped α-AsP as high sensitivity and selectivity NO and NO2 sensor: A first-principles study

This study aims to develop a newfangled toxic gas (NO and NO2) sensor. The adsorption and gas-sensing performance of toxic gas absorbed on the two-dimension arsenic-phosphorus (α-AsP) monolayer was theoretically researched using the DFT calculations. It is found that α-AsP monolayer has weak adsorption performance, and the single non-metal/metal atom doped AsP systems have weak-physical/strong-chemical adsorption behaviors. However, metallic (Cd, Ag, Au, Pt and Fe) and N co-doped AsP systems exhibit excellent gas sensing performance to NO and NO2 gases. These adsorption systems exhibit enhanced gas-sensing performance by regulating the adsorption energy between weak physical adsorption and strong chemical adsorption. It is worth mentioning that the sensitivity of NO and NO2 adsorption on Cd-N co-doped AsP reaches a surprising 94.908% and 78.291%, respectively. Moreover, we predicted that the CdN-AsP system is suitable for NO and NO2 gas-sensing under multiple gas environment by comparing the selectivity, electronic and adsorption properties. Our work has provided a critical reference to develop the potential gas sensor for NO and NO2 detections.